Both radiator fans should always run
when the AC compressor is engaged
. To check the temperature at which the fan comes on, turn the A/C off and keep the engine running until it reaches normal operating temperature. Most fans should come on when the coolant reaches about 200 to 230 degrees.
Why does fan come on when AC is on?
The thermostat is faulty
. If the fan and the cooling system are running when they shouldn't, there's a chance the thermostat may require a replacement. … If only the fan is running when the AC isn't, there may be a faulty relay switch stopping the settings you enter on the thermostat from being communicated to the fan.
When should AC fan come on?
Your HVAC fan should turn on and off with the rest of your heating and cooling system. It's normal for the fan to kick on
a couple of minutes before heating starts
or to stay on for a couple of minutes after cooling stops, but your fan shouldn't run for hours on its own.
What are the symptoms of a faulty cooling fan switch?
- The engine runs hot or overheats. …
- The cooling fans don't work. …
- The cooling fans keep running. …
- Warning lights. …
- Poor air conditioning performance. …
- Swapping Relays. …
- Measuring the Relay Coil's Resistance. …
- Listening for Noises.
Should radiator fan come on with AC?
When the AC compressor is activated, it is actually expected that the radiator fan runs
. For instance, the radiator fan is needed when the temperature sensor of the cooling fluid in the lower tank reaches approximately 212F.
Is the radiator fan the same as the cooling fan?
The
cooling
fans are mounted on the radiator and work to pull air through the radiator fans to keep the engine cool, especially during idle and low speeds, where air flow through the radiator is significantly less than at road speeds.
Why AC and fan should not be used together?
Run Fan and Air Conditioning at the Same Time
It may seem redundant to run both a fan and the AC together. However, the two work in different ways to cool down your home.
A fan cannot provide the cold air that an air conditioner does
. Just like an A/C cannot provide the circulation of a fan.
Why is my AC fan won't turn off?
The most common reason that your Air Conditioner fan won't turn off is
because a stuck relay keeping the circuit closed
. If it's not the relay, your thermostat likely has a shorted cable or needs to be replaced.
Should I leave my AC fan on circulate?
Keeping the fan on creates an
evener distribution of heating and cooling
, circulating the air if you have cold or hot spots in your house, like a bedroom above a garage. Less frequent starts and stops of the fan can reduce the stress from startup, and potentially help extend its lifespan.
Can you run AC fan with windows open?
While leaving the windows open while the air conditioner runs would be an obvious waste of money,
it is OK to open the windows to allow outside air in and run AC fans
. … Using the fan can help draw in fresh, cool air from an open window and force out stale, stagnant air that has gathered in other areas of the home.
How many hours should AC run per day?
How Long Should You Run Your AC Each Day? During a warm or humid day, an average air conditioning unit should run for about
15 or 20 minutes
. After 20 minutes, the indoor temperature should reach your desired setting and the unit will turn itself off.
What are the symptoms of a bad thermostat?
- Leakage from the mounting surface. Appearance: Seepage, drips or large coolant bleed marks on or around the mounting surface or on the housing. …
- Rust and corrosion. Appearance: Rust and corrosion on the surfaces of the thermostat. …
- Deposit build-up. …
- Map-controlled thermostats.
What are the signs of a bad water pump?
- Overheating. A dead or dying water pump cannot circulate coolant through your vehicle's engine and, as such, the engine will overheat. …
- Coolant Leaks. Coolant leaks from the water pump are common and a clear sign that it's time to replace the pump. …
- Corroded Water Pump. …
- Whining Noises.
How do you test a Thermo fan switch?
Turn on the burner and slowly
increase the water temperature
. The ohmeter should be turned on and have a reading of high resistance. When the water reaches between 180 to 220 degrees Fahrenheit, the switch should turn on and the resistance seen by the ohmmeter should change to zero.
What sensor controls the radiator fan?
On most modern cars, the cooling fan is controlled by
the Engine Control Unit (ECU)
which gets a signal from the coolant temperature sensor.
Can you drive without a radiator fan?
Yes, you can drive your car without a radiator fan
, but you never should. Your vehicle's cooling system is crucial to its performance, and every time your engine overheats, you cause damage.
